Adjust gear backlash at differential assembly

AR35.30-T-0475A

Adjust gear backlash at differential assembly

11.1.10



Removing

1

Remove differential assembly.

AR35.30-T-0432A

Adjust

2

Detach locking plates (4)

3

Loosen mounting bolt (2) of bearing bridge (3)

Put on mounting bolts with a tightenening torque of approx 30 Nm.

4

Loosen threaded rings (1) with a square drift (7)



*312589040700

5

Mount dial indicator (5) with dial indicator holder (6) on rear axle housing



*001589532100



*363589022100

6

Check gear backlash

To do this:

- Mount dial indicator tip with preload on one tooth of the ring gear,

- Turn ring gear several times, and

- Determine gear backlash by alternately rotating the ring gear by hand until the ring gear impinges on a noticeable resistance in each case.

- If necessary, adjust specified value of gear backlash: 

7

Adjust specified value of gear backlash

- By screwing the threaded rings in or out.

- Using a plastic mallet apply gentle blows to the bearing bridge so that no stresses in the bearing arise.

Specified value for gear backlash of ring gear

*BE35.30-N-1001-01G



*312589040700

8

Determine gear backlash at a minimum of two other teeth, correct the adjustment if necessary

 Check gear backlash at three positions offset by 120 °.

9

Remove pinion housing with drive pinion

AR35.30-T-0469A

10

Check friction torque of tapered roller bearings of ring gear

If necessary adjust friction value:

AR35.30-T-0470-04A

The friction value is adjusted by screwing the threaded rings in or out.
Using a plastic mallet apply gentle blows to the bearing bridge so that no stresses in the bearing arise.

*BE35.30-N-1002-01G



*745589012100

11

Install pinion housing with drive pinion

AR35.30-T-0469A

12

Check ring gear/drive pinion contact pattern

AR35.30-T-0475-02A

- In case the contact pattern is OK:

Check gear backlash again, if necessary repeat the adjustment of gear backlash and friction value.

- In case the contact pattern is NOT OK:

Correct contact pattern of ring gear/drive pinion. 

13

Correct contact pattern of ring gear/drive pinion.

Depending on the deviation of the contact pattern determined from the ideal contact pattern an appropriate remedy is to be sought.



Contact pattern at base of tooth flank

13.1

Install thicker shim for the drive pinion

Installed dimension between drive pinion and ring gear must be enlarged

Remove/install pinion housing with drive pinion, then

AR35.30-T-0469A

Check gear backlash and contact pattern again, if necessary repeat the complete adjustment.



Contact at top of tooth flank

13.2

Install a thinner shim for the drive pinion.

Installed dimension between drive pinion and ring gear must be reduced

Remove/install pinion housing with drive pinion

AR35.30-T-0469A

Check gear backlash and contact pattern again, if necessary repeat the complete adjustment.



Contact at heel of tooth

13.3

Rotate threaded rings to move ring gear closer to drive pinion

Check gear backlash, friction value and contact pattern again, if necessary repeat the complete adjustment.



Contact pattern at tooth toe

13.4

Rotate threaded rings to move ring gear further away from drive pinion

Check gear backlash, friction value and contact pattern again, if necessary repeat the complete adjustment.

14

Tighten mounting bolts (2) of bearing bridge (3) with specified tightening torque



*BA35.30-N-1004-03F

15

Install locking plates (1) and mounting bolt (8) with specified tightening torque



*BA35.30-N-1005-03F



Install

16

Install differential assembly

AR35.30-T-0432A

Number

Designation

Rear axle
748.513/ 524 with
crown wheel dia.
 233 mm

BE35.30-N-1001-01G

Specified value for gear backlash of ring gear

mm

0.20...0.28

BE35.30-N-1002-01G

Friction torque for ring gear tapered roller bearing

Nm

3.0 to 3.5

Number

Designation

Rear axle 748.513/524

BA35.30-N-1004-03F

Bolt, differential bearing cap to axle housing

M16 x 1.5

Nm

140

BA35.30-N-1005-03F

Bolt, differential bearing cover with locking plate

Nm

25